+1 on M80 HQI ballasts and Radium 250 watt bulbs. They will give higher PAR with Radium bulbs versus
electronic ballasts and they tend to last a long time.
My Hamilton 250 watt HQI ballasts have been in use for 8+ years and still work great.
http://www.hamiltontechnology.com/item/Metal-Halide-HQI-250-Watt-Assembled-Ballast-378
electronic ballasts and they tend to last a long time.
My Hamilton 250 watt HQI ballasts have been in use for 8+ years and still work great.
http://www.hamiltontechnology.com/item/Metal-Halide-HQI-250-Watt-Assembled-Ballast-378